Apparatus for washing the cargo tanks of ships,particularly oil tankers



3,420,444 PARTICULARLY Sheet Jan. 7, 1969 K. G. AJNEFORS APPARATUS FORWASHING THE CARGO TANKS OF SHIPS ofa OIL TANKERS Filed June 14, 19663,420,444 TICULARLY Sheet 2 of 2 J n- 7, 1969 K. G. AJNEFORS APPARATUSFOR WASHING THE CARGO TANKS OF SHIPS, PAR

I OIL TANKERS Filed June 14, 1966 Fig.2

United States Patent Office 3,420,444 APPARATUS FOR WASHING THE CARGOTANKS F SHIPS, PARTICULARLY OIL TANKERS Karl Gunnar Ajnefors, Goteborg,Sweden, assignor to Salen & Wicander AB, Solna, Sweden, a corporation ofSweden Filed June 14, 1966, Ser. No. 557,450 Claims priority,application Sweden, June 14, 1965, 7,829/65; May 12, 1966, Ser. No.6,534/66 US. Cl. 239-227 3 Claims Int. Cl. B05b 3/14 ABSTRACT OF THEDISCLOSURE The present invention relates to an apparatus for washing thecargo tanks of ships, particularly oil tankers, which apparatus includesa jet nozzle that depends downwardly into the cargo tank and which isconnected to means for both rotating the nozzle about a vertical axisand means for oscillating the nozzle about a horizontal axis between anupper and a lower annular limit position.

Such apparatus are previously known to the art, in which thetank-washing operation is carried out by the use of forceful jets ofwater ejected through a nozzle connected to a source of water underpressure and revolving continuously in one single sense about ahorizontal axis which rotates slowly about a vertical axis so as tocause the water jets successively, or incrementally, to sweep allsurface elements of the bottom, walls and ceiling of the cargo tank.However, it may not always be necessary, or even desirable, to wash allportions of a cargo tank, and in such cases the prior art apparatusoperates at an unreasonably slow rate and involves an unnecessary wasteof water and power.

The present invention has for its object to remedy this drawback byproviding a washing apparatus in which the jet nozzle is arranged, inthe course of its rotary motion about the vertical axis, to execute anoscillatory motion about its horizontal axis between an upper and alower angular limit position. The angular limit positions thus definedare suitably adjustable to enable the width and localization of the zoneto be swept by the water jet to be selected at will, for instance toenable washing of the bottom only of the cargo tank.

For transmitting the desired rotary and oscillatory motions to thenozzle, an operating mechanism is provided which is connected to the jetnozzle through movementtransmitting elements. According to a preferredembodiment of the invention, the operating mechanism is arranged torotate the nozzle at a relatively high rate about the vertical axis, andto oscillate the same at a substantially slower rate about thehorizontal axis, thereby causing the spot of impingement of the jet onthe cargo-tank wall to move along substantially horizontally extendingpaths suitably spaced from one another. In this case, the operatingmechanism may be arranged to rotate the nozzle through severalrevolutions in one sense about the vertical axis, while slowly swingingthe nozzle about its horizontal axis between the two angular limitpositions, thereby causing the jet from the nozzle to sweep thecargotank wall along a helical path within a horizontally closed, butvertically limited zone. As an alternative, the operating mechanism maybe so designed as to turn the nozzle reciprocatorily about the verticalaxis between predetermined angular limit positions, while the nozzle iscarrying out its slow swinging motion about the horizontal axis, wherebythe jet spot on the cargo-tank wall will follow a zigzag path within azone which is delimited laterally, as well. In the preferred embodimentit is of 3,420,444 Patented Jan. 7, 1969 particular advantage to arrangethe operating mechanism in such a way that it will automatically reversethe direction of swinging motion of the jet nozzle at the angular limitpositions so as to cause the zone to be washed alternately from topdownwards and from bottom upwards.

Alternatively, the operating mechanism may be so designed as to causethe jet nozzle to run through a plurality of cycles of oscillation at arelatively high angular velocity about the horizontal axis while turningslowly through one revolution about the vertical axis, thereby causingthe spot of impingement of the water jet on the cargo-tank wall todescribe a serpentine, or wave-shaped, path. In this case, the mechanismshould be so devised as to displace the wave-shaped path laterally by asuitable angular amount per revolution of the jet nozzle about thevertical axis.

Further important features of the invention will become apparent fromthe following description of two embodiments thereof with reference tothe accompanying drawings, in which:

FIGURE 1 illustrates the jet-nozzle mechanism proper in a firstembodiment, the said mechanism being permanently mounted in a cargotank, while FIGURE 2, on a larger scale, illustrates the operatingmechanism which is designed as a detachable unit.

Depending through an aperture formed in the weather deck 10 of thevessel and centrally disposed relative to a cargo tank below this deckis a vertical pipe 13 which, through a pipe extension 12 of slightlylarger diameter, communicates with a branch pipe 14 disposed on deck andto which a water pump, not shown, for instance the cargo pump, isconnected. Pipe 13 is suspended from the deck by means of a flange plate15 welded to the same. At its bottom end pipe 13 is terminated by a pipeextension 17 which is Sealingly rotatable relative to the pipe and has aclosed bottom end. Sealingly and r0- tatably mounted in the side wall ofthe pipe extension 17 is a jet nozzle 18 which is bent through a rightangle at a point which is spaced a short distance from its mounting end.By rotating the pipe extension 17 about the axis of the vertical pipe 13and simultaneously swinging the jet nozzle 18 slowly about thehorizontal axis, the outlet orifice of nozzle 18 can be caused todescribe a helical path, either from top downwards or from bottomupwards, whereby the jet will sweep a wall-surface zone the position andvertical extent of which are determined by the upper and lower angularlimit positions of the nozzle swinging about the horizontal axis.

The turning of the vertical plane of oscillation of the nozzle 18, i.e.,the rotation of pipe extension 17, is effected through the intermediaryof a tubular shaft 20 which is passed down through pipe 13 and has itslower end introduced into a central hole made in the bottom of the pipeextension and welded to this bottom, the upper end of shaft 20projecting upward through an end wall on the extension 12 of pipe 13 ondeck. Axially guided within tube 20 is a rod 25 having its upper endprojecting a certain distance beyond the top end of the tubular shaft.Rod 25 carries at its lower end, which depends beyond the tubular shaft20, a disc 26 which is guided for axial movement 'by means of threeguide rods 27 secured to the bottom of pipe extension 17 and passedthrough corresponding holes made in said plate. Rods 27 carry at theirlower ends a plate 28 formed with a radial projection 29 adapted tolimit the swinging movement of nozzle pipe 18 in the downward direction.The disc 26 connected to rod 25 carries a pivot pin 39 having journalledthereon one end of a link 40 the opposite end of which is pivoted on apin 41 secured to the horizontally extending portion of nozzle 18. Pin41 is disposed in laterally spaced relation to a vertical planeextending in parallel relation to the pin and containing the verticalaxis of rotation of the nozzle pipe, so that upon moving the rod 25upwardly from the position illustrated in FIGURE 1, the nozzle pipe 18will be swung about its horizontal axis through the intermediary of link40 from its downwardly directed position, as shown, to an upper positionas indicated in broken lines.

The operating mechanism shown in FIGURE 2 comprises a frame generallydesignated by 50 and including a bottom member 51 and a top member 52connected to the bottom member by four columns 53. Centrally mounted inthe bottom frame member 51 is a gear wheel 54 which engages a smallergear wheel or pinion 55 secured to a drive shaft 56 which can be rotatedin the desired direction by any suitable motor 57, for instance apneumatic motor. Between two spaced parallel plates 58 inside the topframe member 52 a nut 60 provided with a control wheel 59 is rotatablybut axially nondisplaceably mounted. Passing through the nut 60 inthreaded engagement therewith is a screw-threaded rod or lead-screw 61carrying at its bottom end a shaftconnecting sleeve 62 provided with akey 63. Threaded onto the top end of lead-screw 61 is an adjustment nut64 provided with a knob, as well as a lock nut 65 for this adjustmentnut. The bottom frame member 51 is so designed and dimensioned as toenable the entire operating mechanism to be bodily disposed on, andclamped to, the extension 12 of pipe 13 projecting above the deck bymeans of screws, not shown, engaging holes made in lugs formed on thepipe extension 12. The tubular shaft is then pushed into the hub of gear54 with two keys 67 secured to the gear in diametrically opposedpositions entering corresponding key slots 68 formed in shaft 20, whilethe connecting sleeve 62 is passed over the rod and is secured to thelatter by means of a key 63.

After the operating mechanism unit has thus been mounted in place, rod25, by turning the wheel 59, is moved upward to an extent such as toswing the jet nozzle pipe 18 to its desired lower angular limitposition. Then the motor 57 is started in a direction to cause the rod25 which is rotated together with the tubular shaft 20, to be screweddownward again through nut 60. Obviously, during each revolution of thetubular shaft 20 and rod 25, respectively, about the vertical axis, therod 25 will be displaced axially by a length corresponding to the pitchof the screw thread, thereby swinging the nozzle pipe 18 through acorresponding angle about its horizontal axis. Thus, the jet ejected bythe nozzle will impinge the wall at a spot describing a helical pathfrom top downwards within a horizontally extending zone having avertical width determined by the limit positions of the jet nozzle. Uponreaching the bottom limit position, the direction of rotation of drivemotor 57 may be reversed, after which the jet will sweep the same zonein a helical path from bottom upwards.

It is a simple expedient to make provision for the reversal of the drivemotor at the top and bottom angular limit positions of the jet nozzle tooccur in a completely automatic way. As shown in FIGURE 2, theadjustment nut 64 is formed at its bottom end with an annular flange 70cooperating with two control devices 71 and 72, such as air valves,which control the direction of rotation of the drive motor and arevertically adjustable into different positions. When during the downwardmovement of the rod 25 and lead-screw 61 the annular flange 70 impingesthe control device 71, the direction of rotation of the drive motor willbe reversed so that the rod will again begin to move upwardly, and whenthe upper limit position is reached, the flange will engage the controldevice 72 causing the latter to initiate reversal of the motor to itsoriginal direction of rotation. Arrangements in which the reversal of amotor is controlled by control devices adjustable to desired limitpositions are previously known to the art, and therefore, need not bedescribed here in detail.

By providing the control wheel 59 of nut 60 with gear teeth andconnecting the same to a suitable source of driving power, it ispossible, without reversing the direction of rotation of the tubularshaft 20 and rod 25, to cause the jet nozzle 18 to move in helical pathswhich on swinging downward from top are different from those obtained onswinging upward from bottom. If the wheel 59 is rotated in the samesense as the screw spindle or lead-screw 61 and rod 25, but at thedouble angular velocity, then the axial movement of the rod will bereversed with unchanged speed. The rotation of nut 60 may be effectedfrom the drive shaft 56 through any suitable gear train which may bereleasably coupled to the shaft, although, of course, a separate drivemotor may be employed for this purpose.

It should be understood that the invention is not restricted to theembodiments described in detail hereinbefore, since variousmodifications are conceivable without departing from the scope of theinvention.

I claim:

1. Apparatus for washing the cargo tanks of ships, particularly oiltankers, which comprises:

(a) a first vertical pipe that is adapted to be mounted in the apertureof a weather deck and which depends downwardly into a cargo tank belowsaid weather deck,

(b) a pipe extension located on the bottom end of said first verticalpipe, said pipe extension being mounted on said first vertical pipe sothat it is sealingly rotatable relative to said first vertical pipe,

(c) a jet nozzle sealingly and rotatably mounted in the side wall ofsaid pipe extension, said jet nozzle being bent through approximately aright angle at a point which is spaced a short distance from itsmounting end,

(d) a tubular shaft axially disposed within said first vertical pipe soas to leave an axial passageway therebetween, the upper end of saidtubular shaft extending beyond the upper end of said first vertical pipeand the lower end of said tubular shaft extending below the lower end ofsaid first vertical pipe and being fixedly attached to the bottom sideof said pipe extension,

(e) a rod axially disposed within said tubular shaft,

the upper end of said rod projecting above the upper end of said tubularshaft, and the lower end of said rod extending downwardly below thelower end of said tubular shaft,

(f) a disc fixed to the lower end of said rod,

(g) guide rods secured to the bottom of said pipe extension andextending downwardly therefrom, said guide rods serving to guide saiddisc along an axial path that is parallel to the axis of said rod,

(h) said disc being connected to said nozzle by means of a pivotablelink member,

(i) means for limiting the are through which the jet nozzle mayoscillate about a horizontal axis,

(j) a first means for raising and lowering said rod,

(k) a second means for rotating said tubular shaft,

(1) said first and second means being adapted to operate simultaneouslyso as to rotate said nozzle at a relatively high rate about the verticalaxis while at the same time oscillating the nozzle at a substantiallyslower rate about a horizontal axis, there by causing the spot ofimpingement of the jet on the wall of a cargo tank to move along ahelical path within a horizontally closed but vertically limited zone.

2. Apparatus for washing the cargo tanks of ships,

particularly oil tankers, which comprises:

(a) a jet nozzle which is swingable about a support having a horizontalaxis, (b) said support that has a horizontal axis being in 5 6 turnrotatable about a support having a vertical about the horizontal axiseach time the nozzle has axis, reached its upper or lower angular limitposition. (c) said jet nozzle being adapted, under the control 3. Anapparatus according to claim 2 characterized in of an operatingmechanism connected thereto that the operating mechanism is connected tothe nozzle through movement transmitting means, to execute, through theintermediary of a rotatable and axially dissimultaneously with itsrotary motion about the ver- 5 placeable, screw-threaded rodco-operating with an axtical axis, an oscillatory motion about thehorizonially fixed nut.

t-al axis between an upper and a lower angular limit References CitedPosmon, UNITED STATES PATENTS ((1) said operating mechanism beingarranged to rotate 10 the nozzle through several revolutions in onesingle i fi g 1 x Moiren 239227 direction about the vertical axis whileswinging the 3 3 g 239*227 X nozzle only once between the two angularlimit posi- X 0rd 239*227 X 2,785,008 3/1957 Young 239--227 trons aboutthe horizontal axis, so as to cause the 3 265 30 8/1966 spot ofimpingement of the jet on the cargo-tank 15 9 Hammelmann 239 227 X wallto descnbe substantlally horlzontally extendmg M HENSON WOOD, JR.Primary Examiner paths suitably spaced from one another,

(c) said operating mechanism also being constructed HOWARD NATTER,Assistant Examinerso that while maintaining the direction of rotation Usc1- XR. of the nozzle about the vertical axis, it can reverse 20 239 263264 i the direction of swinging movement of the nozzle

